1. Field of the Invention
The present invention relates to a coating composition and a method for producing the same.
2. Description of Related Art
A magnetic recording medium such as a magnetic tape and the like is composed of a substrate and a magnetic recording layer for magnetic-recording a signal provided on the substrate. Of magnetic recording media, those having high recording density have a magnetic recording layer composed of a non-magnetic layer without a ferromagnetic powder and a magnetic layer with a ferromagnetic powder. Further, there are known multi-layer magnetic recording media having non-magnetic layers and magnetic layers laminated alternately on a substrate.
Magnetic recording media containing an α-alumina powder in these non-magnetic layers and magnetic layers are known.
A non-magnetic layer and a magnetic layer are formed, for example, by mixing a binder, a solvent, (a ferromagnetic powder) with an α-alumina powder, stirring them, to obtain a coating composition, and applying this coating composition on a substrate (Japanese Patent Application Laid-Open (JP-A) No. 2003-141714).
However, in conventional coating compositions, it has been difficult to form a layer, for example, non-magnetic layer, having a surface with high degree of smoothness on a substrate.